The code:
Dim DBS As Database
Dim RST As Recordset
Dim x, y

Set DBS = CurrentDb()
Set RST = DBS.OpenRecordset("temp_table")
DoCmd.SetWarnings False
'MsgBox RST.RecordCount
RST.MoveFirst
y = 0
While Not RST.EOF
    x = RST!tempcount
    DoCmd.RunSQL "UPDATE temp_table SET t1 = " & y & "
WHERE tempcount = " & x & ";"
    y = y + 0.5
    RST.MoveNext
Wend
DoCmd.SetWarnings True

Thanks for the help.

-Mike

1.  In the Microsoft Visual Basic window, choose References from the Tools
menu.

2.  In the list of available references, check "Microsoft DAO 3.6 Object
Library".

3.  Use the Priority buttons to move the entry for "Microsoft DAO 3.6 Object
Library" above the entry for "Microsoft ActiveX Data Objects 2.1 Library".
This is to resolve conflicts between types in DAO and ADO (like Field) that
have the same name.  You can also avoid these conflicts by qualifying your
variable declarations, as in:

Dim fld As DAO.Field

instead of

Dim fld As Field

4.  Click OK.